Instead of chemist job, what about adding chemist innate ability to Machinist in futu

[Nalien]

For Chemist I've always had two ideas;

Thief + Chemist. Steal can effectively get us around the whole consumable cost, either by making a Job which actually creates wealth (thus offsetting the cost of potions), or (more likely) by removing consumables completely; You Steal off an enemy, get a special temporary item/status effect. Then you get Mix, which takes that special temporary item/status effect to make something new. Similar to how Mudra turns into various skills when you "mix" them, Steal would turn into Use. You can Steal multiple items (which stack up as temporary items or status effects) but only use one. Then you unlock Mix and can combine them. Actually that is probably closer to Astrologian than Ninja; Swap Draw for Steal, and Royal Road for Mix.

Jobs which require crafts to unlock. Just like you need Rogue and Pugilist to unlock Ninja, you'd need Rogue and Alchemist to unlock Chemist. Since you'd have Alchemist leveled, it is reasonable to assume you can craft your own consumables. Similar concept works for something like Ranger and consumable arrows; Woodworking + Archer.

Having Machinist focus more on gadgets for buffs (and focus more on Songs with Bard) also works nicely though, though I find that to be more of an Engineer type role than Chemist.